Competitors perform at the Red Bull 400 in Harrachov, Czech Republic on September 13th, 2014.

The Unique Challenge of Red Bull 400 returns in 2018 with 17 Events

© Dan Vojtech/Red Bull Content Pool

Red Bull 400 is the toughest 400m run on the planet, with competitors scaling a dry ski jump, and this year it's expanding to even more events around the world.

As well as the second annual World Championships in Bischofshofen there'll be 16 more competitions, four more than in 2017, including Whistler Mountain, where forest fires prevented the event happening last season. The first three events of this season are all on May 12, 2018 in Finland, Japan and the USA.

But what is Red Bull 400? The answer is: an unbelievably gruelling 400m run up a ski jump at the wrong time of year for winter sports, in the opposite direction to what the jump's designer originally intended.

Click below to see what happened when journalist Dominique Granger tried the event out for herself:

See below for a full calendar of events in 2018:

May 12LahtiFinland
May 12Copper Peak, MIUSA
May 12SapporoJapan
May 20AlmatyKazakhstan
May 26ChaykovskiyRussia
June 2TrondheimNorway
June 30Val di FiemmeItaly
July 14Whistler Mountain, BCCanada
July 21CourchevelFrance
July 28Titisee-NeustadtGermany
August 11HarrachovCzech Republic
August 18ZakopanePoland
August 25BischofshofenAustria
September 15PlanicaSlovenia
September 15Park City, UTUSA
October 20EngelbergSwitzerland
October 27SochiRussia